Robotic Systems, Methods And Software Programs For Modifying Tool Operation Based On Tissue Parameters

Abstract

A computer-implemented surgical planning method is provided. The method includes obtaining anatomical data of an anatomical volume and path data including a tool path along which a tool will move. The method also includes obtaining tool data; merging the path data and the anatomical data; and for a point of the tool path, identifying a location of the point, loading a geometry of the tool at the location, identifying an intersection between the tool and the anatomical volume at the location, determining density values of the anatomical data within the intersection, computing a tool contact factor related to the intersection, setting a planned feed rate factor for the tool based on the density values and the tool contact factor, associating the planned feed rate factor with the point; and outputting cut plan data including the planned feed rate factor associated with the point of the tool path.

1 . A computer-implemented surgical planning method comprising:
 obtaining anatomical data comprising a geometry and density values of an anatomical volume;   obtaining path data comprising a tool path along which a robotic manipulator will move a tool to interact with the anatomical volume, the tool path defined by points between which the tool will successively pass;   obtaining tool data including a geometry of the tool that will interact with the tool path;   merging the path data and the anatomical data; and   for at least one point of the tool path:
 identifying a location of the point relative to the anatomical data, 
 loading, from the tool data, the geometry of the tool at the identified location, 
 at the identified location, identifying an intersection between the geometry of the tool and the anatomical volume, 
 determining density values of the anatomical data within the intersection, 
 computing a tool contact factor related to an interaction between the geometry of the tool and the anatomical volume, 
 setting a planned feed rate factor for the tool based on the determined density values and the computed tool contact factor, and 
 associating the planned feed rate factor with the at least one point; and 
   outputting cut plan data comprising the tool path including the planned feed rate factor associated with the at least one point of the tool path.   
     
     
         2 . The computer-implemented surgical planning method of  claim 1 , wherein obtaining anatomical data further includes obtaining a bone model associated with the anatomical volume. 
     
     
         3 . The computer-implemented surgical planning method of  claim 2 , wherein obtaining path data further includes obtaining the tool path being predetermined based on one or more of:
 a planned resection volume of the bone model of the anatomical volume; and   geometry of an implant model selected for the bone model.   
     
     
         4 . The computer-implemented surgical planning method of  claim 1 , wherein obtaining anatomical data further includes obtaining imaging data including slices of the anatomical volume. 
     
     
         5 . The computer-implemented surgical planning method of  claim 4 , wherein obtaining imaging data further includes obtaining DICOM data comprising intercept and slope values, slice thickness, and patient position at a time of imaging. 
     
     
         6 . The computer-implemented surgical planning method of  claim 4 , wherein at the identified location, identifying the intersection between the geometry of the tool and the anatomical volume further comprises:
 identifying one or more slices of the imaging data exhibiting the intersection between the geometry of the tool and the anatomical volume.   
     
     
         7 . The computer-implemented surgical planning method of  claim 6 , wherein determining density values of the anatomical data within the intersection further comprises:
 for each identified slice, determining radiodensity values of the imaging data located within the intersection; and   collecting radiodensity values located within the intersections of each of the one or more identified slices.   
     
     
         8 . The computer-implemented surgical planning method of  claim 7 , wherein setting the planned feed rate factor for the tool based on the determined density values further comprises:
 calculating a bone mineral density (BMD) factor of the anatomical volume relative to the identified location based on the collected radiodensity values; and   setting the planned feed rate factor for the tool based on the calculated BMD factor.   
     
     
         9 . The computer-implemented surgical planning method of  claim 8 , wherein:
 obtaining imaging data further comprises obtaining CT slices of the anatomical volume; and   the geometry of the tool comprises a 3-D geometry of the tool, and   for the at least one point of the tool path:
 loading the 3-D geometry of the tool at the identified location, and 
 at the identified location, identifying CT slices for which there is a cross-sectional intersection between the 3-D geometry of the tool and the anatomical volume; 
   for each identified CT slice, determining a Hounsfield unit for each pixel within the cross-sectional intersection; and   collecting the Hounsfield units from the pixels within the cross-sectional intersections of each of the identified CT slices.   
     
     
         10 . The computer-implemented surgical planning method of  claim 8 , wherein:
 collecting the radiodensity values located within the intersection of each of the one or more identified slices further includes identifying one or more of: an average, a median, and a maximum radiodensity value from the collected radiodensity values; and   calculating the BMD factor further includes converting the one or more of: the average, the median, and the maximum radiodensity value into the BMD factor.   
     
     
         11 . The computer-implemented surgical planning method of  claim 10 , further comprising, for the at least one point of the tool path, and after identifying slices of the imaging data exhibiting the intersection between the geometry of the tool and the anatomical volume, for each identified slice, computing the tool contact factor by computing an intersection ratio related to the geometry of the tool within the intersection relative to the geometry of the tool outside of the intersection. 
     
     
         12 . The computer-implemented surgical planning method of  claim 11 , wherein converting the one or more of: the average, the median, and the maximum radiodensity value into the BMD factor further comprises multiplying the one or more of: the average, the median, and the maximum radiodensity value with the intersection ratio. 
     
     
         13 . The computer-implemented surgical planning method of  claim 11 , wherein, for each identified slice, determining a quantity of pixels within the geometry of the tool having Hounsfield units exceeding a predetermined threshold. 
     
     
         14 . The computer-implemented surgical planning method of  claim 1 , further comprising:
 calculating a bone mineral density (BMD) factor of the anatomical volume relative to the identified location based on the determined density values; and   wherein setting the planned feed rate factor for the tool based on the determined density values further comprises setting the planned feed rate factor based on the calculated BMD factor.   
     
     
         15 . The computer-implemented surgical planning method of  claim 14 , further comprising:
 accessing a look-up table defining associations between predefined BMD factors and predefined feed rate factors; and   wherein, for the at least one point of the tool path, setting the planned feed rate factor based on the calculated BMD factor further comprises:
 identifying, in the look-up table, the predefined BMD factor that is closest to the calculated BMD factor; and 
 setting the planned feed rate factor based on the predefined feed rate factor associated with the closest identified predefined BMD factor in the look-up table. 
   
     
     
         16 . The computer-implemented surgical planning method of  claim 15 , wherein, for the at least one point of the tool path, setting the planned feed rate factor based on the calculated BMD factor further comprises:
 setting the planned feed rate factor to be a maximum feed rate factor in response to determining that the calculated BMD factor is below a minimum threshold; and/or   setting the planned feed rate factor to be a minimum feed rate factor in response to determining that the calculated BMD factor is above a maximum threshold.   
     
     
         17 . The computer-implemented surgical planning method of  claim 1 , further comprising:
 for one point of the tool path, storing interaction coordinates obtained from the intersection between the geometry of the tool and the anatomical volume at the location of the one point, the interaction coordinates indicative of locations of simulated interaction between the geometry of the tool and the anatomical volume at the location of the one point; and   for a second point of the tool path successive to the one point;
 identifying a location of the second point relative to the anatomical data, 
 loading, from the tool data, the geometry of the tool at the identified location of the second point, 
 at the identified location of the second point, identifying an intersection between the geometry of the tool and the anatomical volume, 
 determining density values of the anatomical data within the intersection at the location of the second point, 
 comparing coordinates of the determined density values to the interaction coordinates; and 
 disregarding any density values having coordinates that are identical to the interaction coordinates. 
   
     
     
         18 . The computer-implemented surgical planning method of  claim 1 , further comprising, for the at least one point of the tool path:
 disregarding any density values located beyond the intersection between the geometry of the tool and the anatomical volume.   
     
     
         19 . The computer-implemented surgical planning method of  claim 1 , further comprising:
 for each point of the tool path:
 identifying the location of the point relative to the anatomical data, 
 loading, from the tool data, the geometry of the tool at the identified location, 
 at the identified location, identifying the intersection between the geometry of the tool and the anatomical volume, 
 determining density values of the anatomical data within the intersection, 
 setting the planned feed rate factor for the tool based on the determined density values, and 
 associating the planned feed rate factor with the point; and 
   wherein outputting the cut plan data further comprises the tool path including the planned feed rate factor associated with each point of the tool path.   
     
     
         20 . A non-transitory computer readable medium, having stored thereon instructions which, when executed by one or more processors, implement a computer-implemented surgical planning software configured to:
 obtain anatomical data comprising a geometry and density values of an anatomical volume;   obtain path data comprising a tool path along which a robotic manipulator will move a tool to interact with the anatomical volume, the tool path defined by points between which the tool will successively pass;   obtain tool data including a geometry of the tool that will interact with the tool path;   merge the path data and the anatomical data; and   for at least one point of the tool path:
 identify a location of the point relative to the anatomical data, 
 load, from the tool data, the geometry of the tool at the identified location, 
 at the identified location, identify an intersection between the geometry of the tool and the anatomical volume, 
 determine density values of the anatomical data within the intersection, 
 compute a tool contact factor related to an interaction between the geometry of the tool and the anatomical volume, 
 set a planned feed rate factor for the tool based on the determined density values and the computed tool contact factor, and 
 associate the planned feed rate factor with the at least one point; and 
   output cut plan data comprising the tool path including the planned feed rate factor associated with the at least one point of the tool path.   
     
     
         21 . The non-transitory computer readable medium of  claim 20 , wherein, when executed, the surgical planning software obtains anatomical data by being further configured to:
 obtain a bone model associated with the anatomical volume; or   obtain imaging data including slices of the anatomical volume.   
     
     
         22 . The non-transitory computer readable medium of  claim 21 , wherein, when executed, the surgical planning software identifies the intersection between the geometry of the tool and the anatomical volume at the identified location by being further configured to:
 identify one or more slices of the imaging data exhibiting the intersection between the geometry of the tool and the anatomical volume.   
     
     
         23 . The non-transitory computer readable medium of  claim 22 , wherein, when executed, the surgical planning software determines density values of the anatomical data within the intersection by being further configured to:
 for each identified slice, determine radiodensity values of the imaging data located within the intersection; and   collect radiodensity values located within the intersections of each of the one or more identified slices.   
     
     
         24 . The non-transitory computer readable medium of  claim 23 , wherein, when executed, the surgical planning software sets the planned feed rate factor for the tool based on the determined density values by being further configured to:
 calculate a bone mineral density (BMD) factor of the anatomical volume relative to the identified location based on the collected radiodensity values; and   set the planned feed rate factor for the tool based on the calculated BMD factor.   
     
     
         25 . The non-transitory computer readable medium of  claim 24 , wherein, when executed, the surgical planning software obtains imaging data by being further configured to obtain CT slices of the anatomical volume; and
 the geometry of the tool comprises a 3-D geometry of the tool, and   for the at least one point of the tool path, the surgical planning software:
 loads the 3-D geometry of the tool at the identified location, and 
 at the identified location, identifies CT slices for which there is a cross-sectional intersection between the 3-D geometry of the tool and the anatomical volume; 
   for each identified CT slice, determines a Hounsfield unit for each pixel within the cross-sectional intersection; and   collects the Hounsfield units from the pixels within the cross-sectional intersections of each of the identified CT slices.   
     
     
         26 . The non-transitory computer readable medium of  claim 24 , wherein the surgical planning software is further configured to:
 collect the radiodensity values located within the intersection of each of the one or more identified slices by being further configured to identify one or more of: an average, a median, and a maximum radiodensity value from the collected radiodensity values; and   calculate the BMD factor by being further configured to convert the one or more of: the average, the median, and the maximum radiodensity value into the BMD factor.   
     
     
         27 . The non-transitory computer readable medium of  claim 26 , wherein the surgical planning software is configured to compute the tool contact factor by computing, for the at least one point of the tool path, and after identifying slices of the imaging data exhibiting the intersection between the geometry of the tool and the anatomical volume, for each identified slice, an intersection ratio related to the geometry of the tool within the intersection relative to the geometry of the tool outside of the intersection. 
     
     
         28 . The non-transitory computer readable medium of  claim 20 , wherein the surgical planning software is further configured to:
 calculate a bone mineral density (BMD) factor of the anatomical volume relative to the identified location based on the determined density values; and   wherein the surgical planning software sets the planned feed rate factor for the tool based on the determined density values by being further configured to set the planned feed rate factor based on the calculated BMD factor.   
     
     
         29 . The non-transitory computer readable medium of  claim 28 , wherein the surgical planning software is further configured to:
 access a look-up table defining associations between predefined BMD factors and predefined feed rate factors; and   wherein, for the at least one point of the tool path, the surgical planning software sets the planned feed rate factor based on the calculated BMD factor by being further configured to:
 identify, in the look-up table, the predefined BMD factor that is closest to the calculated BMD factor; and 
 set the planned feed rate factor based on the predefined feed rate factor associated with the closest identified predefined BMD factor in the look-up table. 
   
     
     
         30 . A surgical system comprising:
 a robotic manipulator configured to support and move a tool; and   a control system coupled to the robotic manipulator, and comprising:
 one or more processors; and 
 a non-transitory computer readable medium, having stored thereon instructions which, when executed by the one or more processors, are configured to:
 obtain anatomical data comprising a geometry and density values of an anatomical volume; 
 obtain path data comprising a tool path along which a robotic manipulator will move a tool to interact with an anatomical volume, the tool path defined by points between which the tool will successively pass; 
 obtain tool data including a geometry of the tool that will interact with the tool path; 
 merge the path data and the anatomical data; and 
 for at least one point of the tool path:
 identify a location of the point relative to the anatomical data, 
 load, from the tool data, the geometry of the tool at the identified location, 
 at the identified location, identify an intersection between the geometry of the tool and the anatomical volume, 
 determine density values of the anatomical data within the intersection, 
 compute a tool contact factor related to an interaction between the geometry of the tool and the anatomical volume, 
 set a planned feed rate factor for the tool based on the determined density values and the computed tool contact factor, and 
 associate the planned feed rate factor with the at least one point; and 
 
 output cut plan data comprising the tool path including the planned feed rate factor associated with the at least one point of the tool path; and 
 
 wherein the control system utilizes the outputted cut plan data to control the robotic manipulator to move the tool along the tool path according to the planned feed rate factor associated with the at least one point of the tool path for enabling the tool to interact with the anatomical volume.